JP2011204731A - Method of bonding optical package and lens, and optical package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of bonding an optical package to a lens which can easily and accurately adjust a distance between the optical package and the lens, and the optical package.SOLUTION: A thermoplastic resin 30 is used to bond a condensing lens 20 to the optical package 1 containing an optical element 3 for integration. First, the thermoplastic resin 30 is disposed between bonding surfaces 4 and 21 of the optical package 1 and the lens 20 to align the optical element 3 with a light axis X of the lens 20 while they are in contact with each other. Then, the thermoplastic resin 30 is heated by a heater 40 to be melted. In addition, a distance between the bonding surfaces 4 and 21 is controlled while applying pressure to the lens 20 toward the optical package 1, and an excess of the thermoplastic resin 30 is discharged together with air bubbles from between the bonding surfaces 4 and 21. By the molding of the thermoplastic resin 30 to a joint 30a, the optical package 1 and the lens 20 are bonded.

Description

  The present invention relates to a bonding method in which a condensing lens is attached to and integrated with an optical package containing an optical element, and an optical package in which the lens is integrated by this bonding method.

  In general, a liquid optical adhesive is used for bonding an optical package containing an optical element and a lens (see, for example, Patent Document 1). In addition, simply applying an adhesive to the bonding location and pressing the members to join them makes it easy for bubbles to enter the bonding surface and the adhesive itself, and it is difficult to escape, so use a centrifugal defoamer, vacuum defoamer, etc. Use to remove bubbles.

  FIG. 10 shows a conventional joining method. In FIG. 10A, the optical package 1 accommodates the optical element 3 mounted on the substrate, and extends the lead electrode 2 to the side. Here, the optical package 1 is made of a translucent resin that seals the optical element 3. First, a liquid ultraviolet curing type optical adhesive (hereinafter referred to as an adhesive) 10 is applied to the upper surface of the optical package 1. When the adhesive 10 has a high viscosity, it is difficult for bubbles to escape, and thus defoaming is performed.

  Subsequently, as shown in FIG. 10B, the optical axis X of the optical package 1 and the lens 20 (indicated by a one-dot chain line in the figure) is aligned in a non-contact state. Subsequently, as shown in FIG. 10C, the lens 20 is placed on the upper surface of the optical package 1 while holding the optical axis X of the optical package 1 and the lens 20, and the height direction is adjusted to change the state. Hold. When the adhesive 10 has a high viscosity, it is difficult for air bubbles that have entered between the lens 20 and the optical package 1 to be removed, so the defoaming process is performed again here. Thereafter, the adhesive 10 is cured by ultraviolet irradiation, and the optical package 1 and the lens 20 are bonded.

JP 2006-339653 A

  The liquid adhesive 10 that has been used conventionally has a thin thickness of the coated surface regardless of whether it is low viscosity or high viscosity, so that the adjustment margin in the height direction (that is, the optical axis direction) of the optical package 1 and the lens 20 is small. There is a problem that it is difficult to adjust the distance between the optical package 1 and the lens 20. An optical package to be incorporated into an ultra-small photoelectric sensor or the like needs to keep the distance between the optical package and the lens within an allowable range, but is difficult to realize due to the above-described problems.

  The present invention has been made to solve the above-described problems, and an optical package and lens bonding method capable of easily and highly accurately adjusting the distance between the optical package and the lens, and the bonding method. An object is to provide an optical package in which a lens is integrated.

  The method for bonding an optical package and a lens according to claim 1 of the present invention includes a first step of disposing a thermoplastic resin between the bonding surfaces of the optical package and the lens, and heating and melting the thermoplastic resin, And a second step of adjusting the distance between the joint surfaces while pressing one or both of the optical package and the lens in the direction of each other.

  The optical package and lens bonding method according to claim 2 of the present invention is a state in which the optical package and the thermoplastic resin, and the thermoplastic resin and the lens are brought into contact between the first step and the second step, respectively. The method further includes a step of aligning the optical elements of the optical package and the optical axis of the lens.

  According to a third aspect of the present invention, there is provided a method for bonding an optical package and a lens, wherein in the second step, excess molten thermoplastic resin is discharged from between the bonding surfaces.

  According to a fourth aspect of the present invention, there is provided a method for joining an optical package and a lens, wherein the thermoplastic resin before melting is a radial portion centering on the shaft portion, the shaft portion having both end surfaces in contact with both joint surfaces of the optical package and the lens. And a plurality of convex portions formed on the surface.

  In the method for bonding an optical package and a lens according to claim 5 of the present invention, the lens bonding surface has a tapered convex shape protruding from the bonding surface, and the thermoplastic resin before melting is formed on the lens bonding surface. It has a concave shape matched to the convex shape.

  According to a sixth aspect of the present invention, an optical package containing an optical element, a condensing lens, and a thermoplastic resin are disposed between the joint surfaces of the optical package and the lens, and are heated and melted. In addition, there is provided a joining portion for joining the optical package and the lens, which is pressed together with the excess of the thermoplastic resin and discharged from between the joining surfaces.

  According to the first aspect of the present invention, the thermoplastic resin is disposed between the joint surface of the optical package and the lens so that the thermoplastic resin is heated and melted, and the distance between the joint surfaces is adjusted while being pressurized. Therefore, it is possible to provide a method for joining an optical package and a lens, which can easily and accurately adjust the distance between the optical package and the lens.

  According to claim 2 of the present invention, the optical package and the thermoplastic resin, and the optical element of the optical package and the optical axis of the lens are aligned in a state where the thermoplastic resin and the lens are in contact with each other. Therefore, optical axis alignment can be performed easily and with high accuracy.

  According to the third aspect of the present invention, since the excess of the molten thermoplastic resin is discharged from between the bonding surfaces, bubbles on each bonding surface between the optical package, the thermoplastic resin, and the lens are removed from the excessive thermoplasticity. By flowing out together with the resin, bubbles at the joint can be reduced.

  According to claim 4 of the present invention, since the thermoplastic resin before melting has a plurality of convex portions formed radially, the contact area between the optical package and the lens is small before melting, Since it spreads radially from the center and flows to the outside together with the bubbles, the bubbles at the joint can be reduced.

  According to the fifth aspect of the present invention, since the tapered convex shape is provided on the joint surface of the lens and the concave shape is provided on the thermoplastic resin, the optical package can be easily obtained by fitting the convex shape and the concave shape. And the lens can be aligned, and the molten thermoplastic resin flows out along the convex shape together with the bubbles, so that bubbles at the joint portion can be reduced.

  According to the sixth aspect of the present invention, the thermoplastic resin is disposed between the bonding surfaces of the optical package and the lens, heated and melted and pressurized, and excess of the thermoplastic resin is discharged from between the bonding surfaces. Since the optical package and the lens are bonded to each other with the molded joint, the distance adjustment between the optical package and the lens and the optical axis alignment can be easily and accurately performed in a state of being in contact with the thermoplastic resin. In addition, it is possible to provide an optical package in which the bubbles at the joint portion are reduced by flowing out the bubbles at each joint surface between the optical package, the thermoplastic resin, and the lens together with the extra thermoplastic resin.

It is a side view explaining the joining method of the optical package and lens which concern on Embodiment 1 of this invention, and shows the state before joining. It is a side view explaining the joining method of the optical package and lens which concern on Embodiment 1 of this invention, and shows the state after joining. It is an external appearance perspective view of the thermoplastic resin for joining an optical package and a lens. It is a side view explaining the joining method of the optical package and lens which concern on Embodiment 2 of this invention, and shows the state before joining. It is a side view explaining the joining method of the optical package and lens which concern on Embodiment 2 of this invention, and shows the state after joining. FIG. 6 is a front view of the lens shown in FIGS. 4 and 5. It is a side view explaining the joining method of the optical package and lens which concern on Embodiment 3 of this invention, and shows the state before joining. It is a side view explaining the joining method of the optical package and lens which concern on Embodiment 3 of this invention, and shows the state after joining. It is a front view of the lens shown in FIG.7 and FIG.8. It is a side view explaining the conventional joining method of an optical package and a lens.

Embodiment 1 FIG.
1 and 2 are side views for explaining a method of joining the optical package 1 and the lens 20 according to Embodiment 1 of the present invention. FIG. 1 shows a state before joining, and FIG. 2 shows a state after joining. . In FIG. 1, an optical package 1 is formed by sealing an optical element 3 on a substrate with a light-transmitting resin in the same manner as the optical package 1 shown in FIG. As the optical element 3, a light receiving element, a light projecting element (for example, Light Emitting Diode) or the like is used. Note that the illustrated example is a schematic diagram, and details of wires and the like that connect the optical element 3 and the substrate are omitted. Moreover, the thermoplastic resin 30, the joint part 30a, and the heater 40 show a cross section.

  FIG. 3 is an external perspective view of a thermoplastic resin 30 that serves as an adhesive for joining the optical package 1 and the lens 20. This thermoplastic resin 30 is melted by applying heat and becomes solid again at room temperature. However, the melting point or glass transition temperature of the material of the lens 20 and the material of the optical package 1 is higher than the melting temperature of the thermoplastic resin 30. For example, acrylic resin (PMMA, refractive index: 1.49, glass transition temperature: minus several degrees to several tens of degrees) as the thermoplastic resin 30, polycarbonate (refractive index: 1.585, melting point: 250 degrees) as the lens 20, and Polyarylate (refractive index: 1.61, glass transition temperature: 193 degrees) or the like is used. Further, an epoxy resin (thermosetting resin), a silicon resin, or the like is used as the optical package 1.

  The shape of the thermoplastic resin 30 includes a solid shaft portion 31 and a plurality of convex portions 32 to 35 that are radially formed around the shaft portion 31. In the example of FIG. 3, the angle between the convex portions 32 to 35 is 90 degrees to form a cross-shaped cross section. However, the present invention is not limited to this. For example, three convex portions are formed at intervals of 120 degrees. Alternatively, it may have a star shape in cross section. The thermoplastic resin 30 is disposed between the joint surfaces 4 and 21 such that both end surfaces of the shaft portion 31 are in contact with the joint surface 4 of the optical package 1 and the joint surface 21 of the lens 20.

  In the first embodiment, the thermoplastic resin 30 of FIG. 1 is melted and formed into a joint portion 30a (FIG. 2) for joining the joint surfaces 4 and 21 together. Although details will be described later, a part of the thermoplastic resin 30 flows out from between the joint surfaces 4 and 21, so that the volume of the thermoplastic resin 30 before melting is the joint necessary for joining the joint surfaces 4 and 21. It is necessary to increase the volume of the part 30a.

Next, a joining method will be described.
As shown in FIG. 1, a thermoplastic resin 30 is disposed between the joint surfaces 4 and 21 of the optical package 1 and the lens 20, and the optical package 1, the thermoplastic resin 30, and the lens 20 are in contact with each other in a stable state. The optical axis X of the optical element 3 and the lens 20 (indicated by the alternate long and short dash line in the figure) is aligned. Since alignment is performed in a contact state, optical axis alignment can be performed easily and with high accuracy.

  On the other hand, since a liquid adhesive is conventionally used, it is necessary to align the optical axis of the optical package 1 and the lens 20 in a non-contact state. Therefore, the optical axis alignment operation is not stable, and the repeatability cannot be ensured.

  Subsequently, while heating with the heater 40 to melt the thermoplastic resin 30, the lens 20 is pressed in the direction of the optical package 1 to adjust the distance between the bonding surfaces 4 and 21. Therefore, distance adjustment can be performed easily and with high accuracy. At the time of pressurization, the molten thermoplastic resin 30 is radially spread from the center, and excess thermoplastic resin 30 flows out between the joint surfaces 4 and 21. At the same time, the four spaces (air layers) partitioned by the four convex portions 32 to 35 also flow from the center toward the outside, so that the bubbles at the joint portion between the thermoplastic resin 30 and the joint surfaces 4 and 21 are reduced. be able to. In addition, since the contact area between the thermoplastic resin 30 before melting and the joining surfaces 4 and 21 is small, bubbles existing between the thermoplastic resins 30 and 4 and 21 can be reduced. Since bubbles can be suppressed, it is not necessary to perform a conventional defoaming treatment.

  On the other hand, conventionally, since a liquid adhesive is used, the adjustment distance of the distance between the optical package 1 and the lens 20 is small and adjustment is difficult. Further, when the adhesive had a high viscosity, bubbles were easily generated and it was difficult to remove. When the adhesive has a low viscosity, the thickness of the coated surface is particularly thin, so that bubbles between the optical package 1 and the lens 20 are difficult to escape. For this reason, when the optical package 1 in which the lens 20 is integrated by the conventional bonding method described above is used for, for example, a photoelectric sensor, the expected optical characteristics of the lens 20 cannot be ensured by bubbles, and the photoelectric sensor There was a risk of increasing the distance and increasing the sensitivity.

Subsequently, the state of FIG. 2 is maintained until the thermoplastic resin 30 reaches room temperature, the thermoplastic resin 30 is molded into the shape of the joint portion 30a, and the optical package 1 and the lens 20 are joined via the joint portion 30a. To do.
The heater 40 may be a ring heater, jacket heater, rubber heater, or the like. Further, the heater temperature is controlled so as not to exceed the storage temperature upper limit of the optical package 1. In this example, the lens 20 is pressed in the direction of the optical package 1. However, the present invention is not limited to this, and the optical package 1 may be pressed in the direction of the lens 20. 20 may be pressurized in the direction of each other.

  As described above, according to the first embodiment, the bonding surfaces 4 and 21 of the optical package 1 and the lens 20 are used as a bonding method for bonding and integrating the condensing lens 20 to the optical package 1 in which the optical element 3 is accommodated. A position of the optical axis X of the optical element 3 and the lens 20 in a state where the thermoplastic resin 30 is disposed between the optical package 1 and the thermoplastic resin 30, and the thermoplastic resin 30 and the lens 20 are in contact with each other. A step of performing the alignment, the thermoplastic resin 30 is heated and melted by the heater 40, and the distance between the bonding surfaces 4 and 21 is adjusted while pressing the lens 20 in the direction of the optical package 1, thereby A step of discharging excess of the thermoplastic resin 30 from between 21, a step of maintaining the state and molding the thermoplastic resin 30 into the joint portion 30a to join the optical package 1 and the lens 20; It was configured to include. For this reason, since the thermoplastic resin 30 has a height, the distance between the joining surfaces 4 and 21 can be adjusted easily and with high accuracy by pressurizing the lens 20 while adjusting the height during heating. . Further, the optical axis X of the optical element 3 and the lens 20 can be aligned easily and with high accuracy in a stable state where the bonding surfaces 4 and 21 are in contact with the thermoplastic resin 30.

  Further, according to the first embodiment, the thermoplastic resin 30 before melting includes a shaft portion 31 arranged in parallel to the direction between the joint surfaces 4 and 21 of the optical package 1 and the lens 20, and the shaft portion 31. Since it is configured to have a plurality of convex portions 32 to 35 that are radially formed at the center, the contact area with the joint surfaces 4 and 21 can be reduced, and each joint of the optical package 1, the thermoplastic resin 30, and the lens 20. Bubbles existing on the surface can be reduced. Further, when the thermoplastic resin 30 is melted, it spreads radially from the shaft portion 31 side and flows to the outside together with bubbles, so that bubbles at the joint portion can be reduced.

Embodiment 2. FIG.
4 and 5 are side views for explaining a method of joining the optical package 1 and the lens 20 according to the second embodiment of the present invention. FIG. 4 shows a state before joining, and FIG. 5 shows a state after joining. . FIG. 6 is a front view of the lens 20. 4 to 6, the same or corresponding parts as those in FIGS. 1 and 2 are denoted by the same reference numerals and description thereof is omitted. Further, a part of the lens 20, the thermoplastic resin 36, the joining portion 36a, the heater 40, and the spacer 50 are shown in cross section.

  In the second embodiment, a tapered convex shape 22 projecting toward the thermoplastic resin 36 is formed on the joint surface 21 of the lens 20, and a groove is provided around the convex shape 22, and the groove is melted. The resin receiving portion 23 into which the resin flows is used.

  The thermoplastic resin 36 has a solid cylindrical shape with substantially the same outer diameter as that of the optical package 1, and a concave shape 37 that matches the outer shape of the convex shape 22 is formed on the upper surface of the cylinder facing the lens 20. In the illustrated example, the convex shape 22 is formed in the lens 20 in a conical shape, the apex of the cone is made coincident with the optical axis X of the lens 20, and the conical shape of the convex shape 22 is extracted in one thermoplastic resin 36. A concave shape 37 is formed, and the apex of the cone is made to coincide with the optical axis X of the optical element 3.

  The spacer 50 has an inner diameter that is substantially the same as the outer diameter of the optical package 1. Further, the distance between the optical package 1 and the lens 20 is defined by the height of the spacer 50. In other words, the movement of the lens 20 is restricted when the cemented surface 21 of the lens 20 that moves under pressure comes into contact with the upper surface of the spacer 50.

Next, a joining method will be described.
As shown in FIG. 4, a thermoplastic resin 36 is disposed between the joint surfaces 4 and 21 of the optical package 1 and the lens 20. At this time, the optical package 1 and the thermoplastic resin 36 are aligned by the spacer 50, and the vertex of the concave shape 37 comes on the optical axis X of the optical element 3 at the center of the optical package 1. In addition, the lens 20 and the thermoplastic resin 36 are aligned by fitting the convex shape 22 and the concave shape 37, and the vertex of the convex shape 22 is on the optical axis X of the lens 20. Therefore, the optical axes of the optical element 3 and the lens 20 can be aligned.

  Subsequently, while the thermoplastic resin 36 is melted by heating with the heater 40, the lens 20 is pressed in the direction of the optical package 1 and the bonding surface 21 is pressed against the upper surface of the spacer 50. The distance is adjusted automatically. That is, as shown in FIG. 6, the surface of the bonding surface 21 without the resin receiving portion 23 abuts on the upper surface (not shown) of the spacer 50 and is held at the height position. In addition, during the pressurization, the molten thermoplastic resin 36 rises along the V-shaped surface of the convex shape 22, and excess thermoplastic resin 36 flows out from between the joint surfaces 4 and 21 to the resin receiving portion 23. In this way, the thermoplastic resin 36 is formed into the shape of the joint portion 36a (FIG. 5), and the optical package 1 and the lens 20 are joined via the joint portion 36a.

  As described above, according to the second embodiment, the joint surface 21 of the lens 20 has the tapered convex shape 22 protruding from the joint surface 21, and the thermoplastic resin 36 before melting is the joint surface 21 of the lens 20. Therefore, the optical package 1 and the lens 20 can be easily aligned by fitting the convex shape 22 and the concave shape 37 together. Moreover, since the molten thermoplastic resin 36 flows out along the convex shape 22 along the convex shape 22 from the space between the joint surfaces 4 and 21, the bubbles at the joint portion can be reduced.

  Further, according to the second embodiment, since the movement is restricted by contacting the bonding surface 21 of the lens 20 that moves under pressure, the spacer 50 that adjusts the distance between the bonding surfaces 4 and 21 is provided. The distance between the joining surfaces 4 and 21 can be easily adjusted.

Embodiment 3 FIG.
7 and 8 are side views for explaining a method of joining the optical package 1 and the prism lens 24 according to Embodiment 3 of the present invention. FIG. 7 shows a state before joining, and FIG. 8 shows a state after joining. Show. FIG. 9 is a front view of the prism lens 24. 7 to 9, the same or corresponding parts as those in FIGS. 1 to 6 are denoted by the same reference numerals and description thereof is omitted. Further, a part of the prism lens 24, the thermoplastic resin 38, the joining portion 38a, the heater 40, and the spacer 51 show cross sections.

  In the third embodiment, as in the second embodiment, a tapered convex shape 22 that protrudes toward the thermoplastic resin 38 is formed on the joint surface 21 of the prism lens 24, and a groove is formed around the convex shape 22. The resin receiving portion 23 into which molten resin flows is provided.

  The thermoplastic resin 38 has a solid cylindrical shape with an outer diameter larger than the outer diameter of the optical package 1, and a concave shape 37 having an outer shape larger than the outer shape of the convex shape 22 on the upper surface of the cylinder facing the prism lens 24. Form. In the illustrated example, the convex shape 22 is formed in the prism lens 24 in a substantially conical shape, and the apex of the substantially conical shape is made to coincide with the optical axis X of the prism lens 24, and the one thermoplastic resin 38 has a convex shape 22. A concave shape 37 having a substantially conical shape with a large degree of fitting is formed.

  The spacer 51 has an inner diameter that is larger than the outer diameters of the optical package 1 and the thermoplastic resin 38, and the height defines the distance between the optical package 1 and the prism lens 24.

Next, a joining method will be described.
As shown in FIG. 7, a thermoplastic resin 38 is disposed between the joint surfaces 4 and 21 of the optical package 1 and the prism lens 24. At this time, the apex of the concave shape 37 of the thermoplastic resin 38 and the optical axis X of the optical element 3 are aligned in a stable state where the thermoplastic resin 38 and the optical package 1 are in contact. Further, the lens 20 and the thermoplastic resin 36 are aligned by fitting the convex shape 22 and the concave shape 37, and the vertex of the convex shape 22 is on the optical axis X of the prism lens 24. Therefore, the optical element 3 and the prism lens 24 can be aligned.

  Subsequently, while the thermoplastic resin 38 is melted by heating with the heater 40, the prism lens 24 is pressed in the direction of the optical package 1 to press the bonding surface 21 against the upper surface of the spacer 51, thereby The distance is automatically adjusted. That is, as shown in FIG. 9, the surface of the bonding surface 21 without the resin receiving portion 23 abuts on the upper surface (not shown) of the spacer 51 and is held at the height position. In addition, during the pressurization, the molten thermoplastic resin 38 rises along the V-shaped surface of the convex shape 22, and excess thermoplastic resin 38 flows out from between the joint surfaces 4 and 21 to the resin receiving portion 23. In this way, the thermoplastic resin 38 is formed into the shape of the joint portion 38a (FIG. 8), and the optical package 1 and the prism lens 24 are joined via the joint portion 38a.

  As described above, according to the third embodiment, the joint surface 21 of the prism lens 24 has the tapered convex shape 22 protruding from the joint surface 21, and the thermoplastic resin 38 before melting is joined to the prism lens 24. The concave shape 37 matched with the convex shape 22 of the surface 21 was configured. Therefore, even when the prism lens 24 is bonded to the optical package 1, the alignment can be easily performed by fitting the convex shape 22 and the concave shape 37. In addition, since the molten thermoplastic resin 38 flows out of the joint surfaces 4 and 21 to the outside along the convex shape 22 together with the bubbles, the bubbles in the joint portion can be reduced.

DESCRIPTION OF SYMBOLS 1 Optical package 2 Lead electrode 3 Optical element 4 Joint surface 10 Adhesive 20 Lens 21 Joint surface 22 Convex shape 23 Resin receiving part 24 Prism lens 30, 36, 38 Thermoplastic resin 30a, 36a, 38a Joint part 31 Shaft part 32- 35 Convex part 37 Concave shape 40 Heater 50, 51 Spacer X Optical axis

Claims (6)

A method for joining an optical package and a lens, in which a condensing lens is joined to and integrated with an optical package containing an optical element,
A first step of disposing a thermoplastic resin between a bonding surface of the optical package and the lens;
A second step of heating and melting the thermoplastic resin and adjusting a distance between the joint surfaces while pressing one or both of the optical package and the lens in the direction of each other. A method of joining an optical package and a lens.   Between the first step and the second step, the optical package and the thermoplastic resin, and the alignment of the optical element of the optical package and the optical axis of the lens with the thermoplastic resin and the lens in contact with each other The method for bonding an optical package and a lens according to claim 1, further comprising:   2. The method for bonding an optical package and a lens according to claim 1, wherein, in the second step, the excess of the molten thermoplastic resin is discharged from between the bonding surfaces.   The thermoplastic resin before melting has a shaft portion whose both end surfaces are in contact with both joint surfaces of the optical package and the lens, and a plurality of convex portions formed radially around the shaft portion. The method for bonding an optical package and a lens according to any one of claims 1 to 3. The joint surface of the lens has a tapered convex shape protruding from the joint surface,
5. The optical package and the lens according to claim 1, wherein the thermoplastic resin before melting has a concave shape that matches a convex shape of a joint surface of the lens. Joining method. An optical package containing the optical element;
A condensing lens;
The optical resin in which the thermoplastic resin is disposed between the joint surfaces of the optical package and the lens, is heated and melted and pressed to discharge excess thermoplastic resin from the joint surfaces, and is molded. An optical package comprising a package and a joint that joins the lens.

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